The grubby white Essex Police van was straddling two spaces and would have irritated motorists looking for a space in the village of Boreham.

But he was soon taking flak. "If this is what fills your day, boss, I'm really worried about your priorities," said one observer on Twitter.

"It doesn't fill my day. Apologising to the public when we get it wrong is part of policing," Constable Kavanagh replied.

"Get out on the streets & do somat useful instead of grovelling to the public," said another Twitter user. Others suggested that the berth-straddling may have been necessary to allow passengers to get out of the adjacent car.

But Steve Taylor, chair of Essex Police Federation, defended his colleague.This has certainly captured people's imagination, but, as the leader of our force we look to the chief constable to set the standards when it comes to expectations of how we should behave," he told the BBC.

"I'm not going to condemn him for sharing his values and expectations with his workforce. He's just asking us to be mindful of who we are and how we carry ourselves."

A spokesman for Essex Police said the driver had been been ticked off.

"We expect anyone driving a police vehicle to be beyond reproach and show extra special consideration and courtesy to pedestrians and other cars when parking. The member of police staff who parked inconsiderately in Boreham has been spoken to and reminded of the need to uphold a higher standard."